The expanding use of supplemental inflatable restraints (SIRs) or air bags for occupant protection in vehicles increasingly involves equipment for the front outboard passenger seat. The driver side air bag has been deployed whenever an imminent crash is sensed. The position and size of the driver is fairly predictable so that such deployment can advantageously interact with the driver upon a crash. The passenger seat, however, may be occupied by a large or a small occupant including a baby in an infant seat. It can not be assumed that a passenger of any size is at an optimum position (leaning against or near the seat back). An infant seat is normally used in a rear facing position for small babies and in a forward facing position for larger babies and small children. While the forward facing position approximates the preferred position for air bag interaction, the rear facing position places the top portion of the infant seat close to the vehicle panel which houses the passenger side air bag. In the latter event, it may be desirable to prevent deployment of the air bag. Similarly, if a passenger in the seat is leaning forward, it may be desirable to prevent air bag deployment.
It has been proposed to use a magnet or other special attachment on an infant seat and a special sensor in the seat or panelboard which detects the attachment and allows determination that an infant seat is present and is positioned in a particular way. Of course that arrangement is operable only with the specially equipped infant seats; other infant seats and passengers are not serviced. A separate sensing system would have to be employed to detect the position or presence of small children or adults.
Seat belt restraint systems can also benefit by information about the presence of passengers. For example, by monitoring which belts are buckled and which seats are occupied, a warning display can inform the driver that some seat or a particular seat is occupied and the belt is not utilized. Where an infant seat is in a vehicle seat and the infant seat is occupied, this seat also should be belted in and the warning system employed to detect a failure to meet this condition.